title: Methylation regulation of liver-specific microRNA-122 expression and its effects on the proliferation and apoptosis of hepatocellular carcinoma cells.
abstract: The regulation mechanism and significance of microRNA-122 (miRNA-122) expression are unclear. The aim of this study was to investigate the effects of DNA methylation on liver-specific miRNA-122 expression, cell proliferation, and apoptosis in hepatocellular carcinoma. Methylation of the miRNA-122 promoter region was detected through methylation sequencing. The level of miRNA-122 expression was measured using real-time quantitative polymerase chain reaction. The proliferation and apoptosis of hepatocellular cell lines were detected using flow cytometry and Cell Counting Kit-8 assays. Compared with those in human primary hepatocytes, methylation levels of the miRNA-122 promoter in the Huh7, HepG2, and QSG-7701 cell lines were significantly increased (P = 0.000). Similarly, levels of miRNA-122 expression in these cell lines significantly decreased (P = 0.007). After treatment with 5-aza-2-deoxycytidine, the Huh7 and HepG2 cell lines displayed a significantly lower degree of methylation (P = 0.038 and 0.025), and the levels of miRNA-122 expression were significantly higher (P = 0.008 and 0.003) than those in the blank group. Compared with the blank group, apoptosis of Huh7 and HepG2 cells was significantly increased (P = 0.001 and 0.027). We concluded that the expression of miRNA-122 is regulated by DNA methylation and correlated with apoptosis of liver cancer cells. Methylation regulation of miRNA-122 expression might be involved in the development of hepatocellular carcinoma.
authors.affiliation: Department of Infectious Diseases, Taizhou People's Hospital, Taizhou, China xingtj518@sina.com.
authors.forename: T J
authors.initials: TJ
authors.lastname: Xing
authors.forename: H T
authors.initials: HT
authors.lastname: Xu
authors.forename: W Q
authors.initials: WQ
authors.lastname: Yu
authors.forename: D F
authors.initials: DF
authors.lastname: Jiang
mesh_terms: D000964:Antimetabolites, Antineoplastic / Q000494:pharmacology; D017209:Apoptosis / Q000235:genetics*; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D006528:Carcinoma, Hepatocellular / Q000378:metabolism; D045744:Cell Line, Tumor; D049109:Cell Proliferation; D019175:DNA Methylation; D000077209:Decitabine; D015972:Gene Expression Regulation, Neoplastic; D022781:Hepatocytes / Q000378:metabolism; D006801:Humans; D008099:Liver / Q000166:cytology / Q000378:metabolism; D008113:Liver Neoplasms / Q000378:metabolism; D035683:MicroRNAs / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic
chemical_list: D000964:Antimetabolites, Antineoplastic; C531907:MIRN122 microRNA, human; D035683:MicroRNAs; D000077209:Decitabine; D001374:Azacitidine